Synthesis and liquid membrane transport properties of photolabile molecular clips based on dithiane-spiro-crown ethers.

[reaction: see text]. Synthesis of novel dithiane-spiro-crown ethers starting from 5,5-di(hydroxymethyl)-1,3-dithiane is developed. These compounds can be used as building blocks to assemble photolabile bis-crown ethers via addition to dicarbonyl-containing tethers, e.g., isophthalic aldehyde. It is found that unlike their mono-crown precursors such bidentate bis-crowns are capable of efficient liquid membrane transport of, for example, methyl viologen. The transport can be interrupted photochemically, providing a basis for developing smart light-responsive membranes.